Liquid Crystal Display Device and Television Set

ABSTRACT

A backlight includes light emitting diodes; a substrate on which light emitting diodes are mounted; and a reflection sheet. The surface on which the light emitting diodes are mounted of the substrate is opposed to a rear surface of the liquid crystal display panel. The liquid crystal display panel and the substrate each have a shape in which a common width in a first direction is longer than a width in a second direction, which is orthogonal to the first direction. The width of the substrate in the second direction is shorter than the width of the liquid crystal display panel in the second direction. The substrate is opposed to, while avoiding being opposed to both end portions of the liquid crystal display panel in the second direction, a central portion between the both end portions of the liquid crystal display panel.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.13/094,862, filed Apr. 27, 2011, the contents of which are incorporatedherein by reference.

This application is a continuation application of InternationalApplication PCT/JP2011/051308, filed on Jan. 25, 2011, and designatingthe US. This application claims priority from Japanese applicationJP2010-138555 filed on Jun. 17, 2010, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device and atelevision set.

2. Description of the Related Art

Light emitting diodes have become widely used as a light source of abacklight. For example, there is known an edge light type backlight inwhich, instead of cold-cathode tubes, light emitting diodes are disposedon an end surface of a light guide plate so as to enable surfaceemission by the light guide plate. Further, there is known an exampleusing light emitting diodes in a direct type backlight (Japanese PatentApplication Laid-open No. 2009-87879).

In a conventional direct type backlight, light emitting diodes arearranged in a region opposed to an entire surface of a liquid crystaldisplay panel. Therefore, a large substrate for light emitting diodes isnecessary, and hence it has been difficult to reduce the number ofcomponents to be used and to reduce cost.

SUMMARY OF THE INVENTION

The present invention has an object to provide a backlight in which asize of a substrate for light emitting diodes can be reduced and costcan be reduced, and a television set using the backlight.

(1) A liquid crystal display device according to the present inventionincludes: a liquid crystal display panel having a display surface and arear surface, which is on a side opposite to the display surface; and abacklight, in which: the backlight includes: a plurality of lightemitting diodes; a substrate on which the plurality of light emittingdiodes are mounted; and a reflection sheet, which overlaps the substrateat a surface on which the plurality of light emitting diodes are mountedin a manner without overlapping the plurality of light emitting diodes;the surface on which the plurality of light emitting diodes are mountedof the substrate is opposed to the rear surface of the liquid crystaldisplay panel; the liquid crystal display panel and the substrate eachhave a shape in which a common width in a first direction is longer thana width in a second direction, which is orthogonal to the firstdirection; and the width of the substrate in the second direction isshorter than the width of the liquid crystal display panel in the seconddirection, the substrate being opposed to, while avoiding being opposedto both end portions of the liquid crystal display panel in the seconddirection, a central portion between the both end portions of the liquidcrystal display panel. According to the present invention, the substrateon which the light emitting diodes are mounted is small in size, andhence cost reduction is possible.

(2) In the liquid crystal display device as described in Item (1) of thepresent invention, the width of the substrate in the second directionmay be one-third the width of the liquid crystal display panel in thesecond direction or less.

(3) In the liquid crystal display device as described in Item (1) or (2)of the present invention, each of the liquid crystal display panel andthe substrate may have a rectangular shape which is long in the firstdirection.

(4) In the liquid crystal display device as described in any one ofItems (1) to (3) of the present invention, the plurality of lightemitting diodes may be arranged in a row in the first direction.

(5) In the liquid crystal display device as described in Item (4) of thepresent invention, pitches between adjacent light emitting diodes of theplurality of light emitting diodes may be equal.

(6) In the liquid crystal display device as described in Item (4) of thepresent invention, pitches between adjacent light emitting diodes of theplurality of light emitting diodes may be smaller as the adjacent lightemitting diodes are closer to a center of the substrate in the firstdirection.

(7) In the liquid crystal display device as described in any one ofItems (1) to (3) of the present invention, the plurality of lightemitting diodes may be arranged in a staggered pattern in the firstdirection.

(8) In the liquid crystal display device as described in Item (7) of thepresent invention, pitches between adjacent light emitting diodes of theplurality of light emitting diodes in an arrangement direction of thestaggered pattern may be equal.

(9) In the liquid crystal display device as described in Item (7) of thepresent invention, pitches between adjacent light emitting diodes of theplurality of light emitting diodes in an arrangement direction of thestaggered pattern may be smaller as the adjacent light emitting diodesare closer to a center of the substrate in the first direction.

(10) In the liquid crystal display device as described in any one ofItems (1) to (3) of the present invention, the plurality of lightemitting diodes may include light emitting diodes in a first group,which are arranged in a row in the first direction, and light emittingdiodes in a second group, which are arranged in a staggered pattern inthe first direction.

(11) In the liquid crystal display device as described in Item (10) ofthe present invention: the light emitting diodes in the second group maybe disposed at a central portion of the substrate in the firstdirection; and the light emitting diodes in the first group may berespectively disposed at both end portions of the substrate, whichsandwich the central portion.

(12) In the liquid crystal display device as described in Item (11) ofthe present invention: the light emitting diodes in the first group maybe arranged at equal pitches in the first direction; and the lightemitting diodes in the second group may be arranged at equal pitches inan arrangement direction of the staggered pattern.

(13) In the liquid crystal display device as described in Item (11) ofthe present invention: pitches between adjacent light emitting diodes ofthe light emitting diodes in the first group may be smaller as theadjacent light emitting diodes are closer to a center of the substratein the first direction; and pitches between adjacent light emittingdiodes of the light emitting diodes in the second group in anarrangement direction of the staggered pattern may be smaller as theadjacent light emitting diodes are closer to the center of the substratein the first direction.

(14) In the liquid crystal display device as described in any one ofItems (11) to (13) of the present invention, a width of the substrate inthe second direction at the central portion may be larger than a widthof the substrate in the second direction at each of the both endportions.

(15) In the liquid crystal display device as described in any one ofItems (1) to (3) of the present invention: pitches between adjacentlight emitting diodes of the plurality of light emitting diodes may besmaller as the adjacent light emitting diodes are closer to a center ofthe substrate in the first direction; the substrate may be divided intoa first divided substrate and a second divided substrate betweenadjacent light emitting diodes having a smallest pitch among thepitches; at least one of the first divided substrate and the seconddivided substrate may include, at one end portion of the at least one ofthe first divided substrate and the second divided substrate, a cableconnector for connection to a cable; and the first divided substrate andthe second divided substrate may be disposed so that another end portionof the first divided substrate and another end portion of the seconddivided substrate are adjacent to each other.

(16) In the liquid crystal display device as described in Item (15) ofthe present invention, the first divided substrate and the seconddivided substrate may have the same design, and have a positionalrelationship of rotation symmetry to each other.

(17) In the liquid crystal display device as described in Item (16) ofthe present invention: the another end portion of the first dividedsubstrate and the another end portion of the second divided substratemay each have a recess portion and a convex portion at surfaces whichare opposed to each other; and the first divided substrate and thesecond divided substrate may be disposed so that the recess portion ofone divided substrate is opposed to the convex portion of anotherdivided substrate.

(18) In the liquid crystal display device as described in Item (17) ofthe present invention: the plurality of light emitting diodes may bearranged in a staggered pattern in the first direction at least on theanother end portion side of the first divided substrate, at which therecess portion and the convex portion are formed, and on the another endportion side of the second divided substrate, at which the recessportion and the convex portion are formed; and the convex portion may beprotruded in the first direction from one of the plurality of lightemitting diodes, which is positioned outermost in the first direction ofeach of the first divided substrate and the second divided substrate.

(19) In the liquid crystal display device as described in any one ofItems (1) to (3) of the present invention: pitches between adjacentlight emitting diodes of the plurality of light emitting diodes may besmaller as the adjacent light emitting diodes are closer to a center ofthe substrate in the first direction; the substrate may be divided intoa first divided substrate and a second divided substrate betweenadjacent light emitting diodes provided at a position away from aposition at which adjacent light emitting diodes having a smallest pitchamong the pitches are provided; at least one of the first dividedsubstrate and the second divided substrate may include, at one endportion of the at least one of the first divided substrate and thesecond divided substrate, a cable connector for connection to a cable;and the first divided substrate and the second divided substrate may bedisposed so that another end portion of the first divided substrate andanother end portion of the second divided substrate are adjacent to eachother.

(20) In the liquid crystal display device as described in any one ofItems (1) to (3) of the present invention: pitches between adjacentlight emitting diodes of the plurality of light emitting diodes may besmaller as the adjacent light emitting diodes are closer to a center ofthe substrate in the first direction; the substrate may be divided intoa first divided substrate, a second divided substrate, and a thirddivided substrate between adjacent light emitting diodes provided atpositions away from a position at which adjacent light emitting diodeshaving a smallest pitch among the pitches are provided; and the liquidcrystal display device may further include: a cable connector forconnection to a cable, which is provided at one end portion of the firstdivided substrate; a first substrate connector for electricallyconnecting another end portion of the first divided substrate and oneend portion of the second divided substrate; and a second substrateconnector for electrically connecting another end portion of the seconddivided substrate and one end portion of the third divided substrate.

(21) In the liquid crystal display device as described in Item (20) ofthe present invention: the plurality of light emitting diodes may bearranged in a staggered pattern in the first direction; and the pitchesbetween adjacent light emitting diodes of the plurality of lightemitting diodes may correspond to pitches between adjacent lightemitting diodes of the plurality of light emitting diodes in anarrangement direction of the staggered pattern.

(22) In the liquid crystal display device as described in Item (21) ofthe present invention: the another end portion of the first dividedsubstrate and the one end portion of the second divided substrate, whichare electrically connected to each other, may each have a recess portionand a convex portion at surfaces which are opposed to each other; theanother end portion of the second divided substrate and the one endportion of the third divided substrate, which are electrically connectedto each other, may each have a recess portion and a convex portion atsurfaces which are opposed to each other; the convex portion may beprotruded in the first direction from one of the plurality of lightemitting diodes, which is positioned outermost in the first direction ofeach of the first divided substrate, the second divided substrate, andthe third divided substrate; the first divided substrate and the seconddivided substrate may be disposed so that the recess portion of onedivided substrate is opposed to the convex portion of another dividedsubstrate; and the second divided substrate and the third dividedsubstrate may be disposed so that the recess portion of one dividedsubstrate is opposed to the convex portion of another divided substrate.

(23) In the liquid crystal display device as described in Item (20) ofthe present invention: light emitting diodes, which are disposed on thesecond divided substrate, of the plurality of light emitting diodes maybe arranged in a staggered pattern in the first direction, and pitchesbetween adjacent light emitting diodes of the light emitting diodes maycorrespond to pitches between adjacent light emitting diodes of thelight emitting diodes in an arrangement direction of the staggeredpattern; and light emitting diodes, which are disposed on the firstdivided substrate, and light emitting diodes, which are disposed on thethird divided substrate, of the plurality of light emitting diodes maybe respectively arranged in a row in the first direction.

(24) In the liquid crystal display device as described in Item (23) ofthe present invention, a width of the second divided substrate in thesecond direction may be larger than any one of a width of the firstdivided substrate in the second direction and a width of the thirddivided substrate in the second direction.

(25) In the liquid crystal display device as described in any one ofItems (1) to (3) of the present invention: the backlight may include thereflection sheet as a first reflection sheet, and a second reflectionsheet, which is adhered to the substrate; the first reflection sheet mayinclude a plurality of first holes, which allow the plurality of lightemitting diodes to be respectively disposed on inner sides of the firstreflection sheet; the second reflection sheet may include, as a whole, aplurality of second holes, which allow the plurality of light emittingdiodes to be respectively disposed on inner sides of the secondreflection sheet; and on an inner side of each of the plurality of firstholes, at least a part of an edge portion of corresponding one of theplurality of second holes may be exposed.

(26) In the liquid crystal display device as described in Item (25) ofthe present invention: the second reflection sheet may be divided into aplurality of reflection pieces; one of the plurality of reflectionpieces may include one of the plurality of second holes, which allowsone of the plurality of light emitting diodes to be disposed on an innerside of the one of the plurality of reflection pieces; pitches betweenadjacent light emitting diodes of the plurality of light emitting diodesmay be smaller as the adjacent light emitting diodes are closer to acenter of the substrate in the first direction; and each of theplurality of reflection pieces may be formed in such a size and a shapethat, at a position corresponding to adjacent light emitting diodeshaving a smallest pitch among the pitches, adjacent reflection piecesare provided without overlapping each other.

(27) In the liquid crystal display device as described in Item (25) ofthe present invention: the second reflection sheet may be divided into afirst reflection piece, which is disposed in a first region at a centerof the substrate, and a plurality of second reflection pieces, which aredisposed at a pair of second regions of the substrate, which sandwichthe first region; and pitches between adjacent light emitting diodes ofthe plurality of light emitting diodes may be smaller as the adjacentlight emitting diodes are closer to the center of the substrate in thefirst direction.

(28) In the liquid crystal display device as described in Item (27) ofthe present invention: the first reflection piece may include at leasttwo of the plurality of second holes; and each of the plurality ofsecond reflection pieces may include one of the plurality of secondholes.

(29) In the liquid crystal display device as described in Item (27) ofthe present invention: the first reflection piece may include at leasttwo of the plurality of second holes; and each of the plurality ofsecond reflection pieces may include at least two of the plurality ofsecond holes.

(30) In the liquid crystal display device as described in any one ofItems (27) to (29) of the present invention, at least the light emittingdiodes, which are disposed in the first region, may be arranged in astaggered pattern in the first direction.

(31) In the liquid crystal display device as described in Item (30) ofthe present invention, the light emitting diodes, which are disposed inthe second region, may be arranged in a row in the first direction.

(32) In the liquid crystal display device as described in Item (25) ofthe present invention: the second reflection sheet may be divided into aplurality of reflection pieces; each of the plurality of reflectionpieces may include at least two of the plurality of second holes, whichallow at least two of the plurality of light emitting diodes to bedisposed on inner sides of the at least two of the plurality ofreflection pieces; the substrate may be divided into a plurality ofdivided substrates; and each of the plurality of reflection pieces mayhave an outer shape which is similar to one of the plurality of dividedsubstrates to which corresponding one of the plurality of reflectionpieces is adhered.

(33) In the liquid crystal display device as described in Item (25) ofthe present invention, the second reflection sheet may be formed byapplying a white resist onto the substrate.

(34) In the liquid crystal display device as described in any one ofItems (1) to (32) of the present invention: the liquid crystal displaydevice may further include: a support plate, which supports thesubstrate on a side opposite to the plurality of light emitting diodesand is larger in size than the substrate; and a lens disposed above thesubstrate and above at least one of the plurality of light emittingdiodes; and the lens may be attached to the support plate on an outerside of the substrate.

(35) In the liquid crystal display device as described in Item (34) ofthe present invention: the liquid crystal display device may furtherinclude a spacer provided on the support plate; and the lens may besupported by the support plate through intermediation of the spacer.

(36) In the liquid crystal display device as described in any one ofItems (1) to (32) of the present invention: the liquid crystal displaydevice may further include: a plurality of the substrates; a supportplate, which supports the plurality of the substrates on a side oppositeto the plurality of light emitting diodes and is larger in size than theplurality of the substrates; and a lens disposed above each of theplurality of the substrates and above at least one of the plurality oflight emitting diodes; and each of the lenses may be attached to thesupport plate on an outer side of corresponding one of the plurality ofthe substrates.

(37) In the liquid crystal display device as described in Item (36) ofthe present invention: the liquid crystal display device may furtherinclude a spacer provided on the support plate; and the lenses may besupported by the support plate through intermediation of the spacer.

(38) In the liquid crystal display device as described in Item (37) ofthe present invention: the spacer may be disposed at least without beingdivided between adjacent substrates of the plurality of the substrates;and both of the lens positioned above one of the adjacent substrates andthe lens positioned above another of the adjacent substrates may besupported by the spacer disposed between the adjacent substrates.

(39) In the liquid crystal display device as described in Item (37) ofthe present invention: the spacer may be divided into at least a firstdivided spacer and a second divided spacer between adjacent substratesof the plurality of the substrates, the first divided spacer beingdisposed near one of the adjacent substrates, the second divided spacerbeing disposed near another of the adjacent substrates; the lenspositioned above the one of the adjacent substrates may be supported bythe first divided spacer; and the lens positioned above the another ofthe adjacent substrates may be supported by the second divided spacer.

(40) In the liquid crystal display device as described in Item (1) ofthe present invention, the reflection sheet corresponding to a firstreflection sheet may have a curved portion.

(41) A television set according to the present invention includes theliquid crystal display device according to any one of Items (1) to (40)of the present invention, the television set being formed so as toreceive a radio wave for television broadcast to display an image andoutput sound.

(42) A television set according to the present invention includes: aliquid crystal display panel having a screen which is horizontally long;a backlight, which overlaps the liquid crystal display panel; a speaker;and a tuner, in which: the backlight includes: a reflection sheet havinga curved portion so that a recess surface of the curved portion facesthe liquid crystal display panel; a substrate on which the reflectionsheet is overlapped on a side opposite to the liquid crystal displaypanel of the reflection sheet; and a plurality of point light sources,which are mounted on the substrate and disposed so as to protrude to therecess surface side while passing through the reflection sheet; each ofthe plurality of point light sources emits light in a perpendiculardirection to the substrate and in other directions, the light emitted inthe other directions being higher in intensity than the light emitted inthe perpendicular direction; and the plurality of point light sourcesare arranged in at least one row in a horizontal direction of thescreen, and arranged so as to be stored within a space region, which hasa width in a vertical direction of the screen, the width being half alength of the screen in the vertical direction or less. According to thepresent invention, although the space occupied by the plurality of pointlight sources in the vertical direction of the screen is small, light isemitted so as to be spread, and smooth brightness change is caused bythe curved portion of the reflection sheet. Therefore, a comfortablebrightness distribution can be obtained.

(43) In the television set as described in Item (42) of the presentinvention, a width of the substrate in the vertical direction of thescreen may be half the length of the screen in the vertical direction orless.

(44) In the television set as described in Item (42) of the presentinvention, the substrate may include a plurality of divided substrateswhich are arranged in the vertical direction of the screen.

(45) In the television set as described in Item (42) of the presentinvention: the curved portion of the reflection sheet may include afirst curved portion and a second curved portion; and the first curvedportion and the second curved portion may be formed on respective sidesof the reflection sheet in the vertical direction of the screen whilesandwiching the plurality of point light sources.

(46) In the television set as described in Item (42) of the presentinvention, each of the plurality of point light sources may include alight emitting diode and a lens disposed on an outer side of the lightemitting diode.

(47) A television set according to the present invention includes: aliquid crystal display panel having a screen which is horizontally long;a backlight, which overlaps the liquid crystal display panel; a speaker;a tuner; and a cabinet for storing at least the liquid crystal displaypanel and the backlight, in which: the backlight includes: a reflectionsheet having a curved portion so that a recess surface of the curvedportion faces the liquid crystal display panel; a substrate on which thereflection sheet is overlapped on a side opposite to the liquid crystaldisplay panel of the reflection sheet; and a plurality of point lightsources, which are mounted on the substrate and disposed so as toprotrude to the recess surface side while passing through the reflectionsheet; the plurality of point light sources are arranged in at least onerow in a horizontal direction of the screen; each of the plurality ofpoint light sources emits light in a perpendicular direction to thesubstrate and in other directions, the light emitted in the otherdirections being higher in intensity than the light emitted in theperpendicular direction; and the substrate is fixed to the cabinet.According to the present invention, light is emitted so as to be spread,and smooth brightness change is caused by the curved portion of thereflection sheet. Therefore, a comfortable brightness distribution canbe obtained, and thinning is achieved by fixing the substrate to thecabinet.

(48) In the television set as described in Item (47) of the presentinvention, the substrate may be directly fixed to the cabinet.

(49) In the television set as described in Item (47) of the presentinvention: the television set may further include a radiator plate towhich the substrate is fixed; the radiator plate may be fixed to thecabinet; and the substrate may be fixed to the cabinet throughintermediation of the radiator plate.

(50) In the television set as described in Item (47) of the presentinvention: the television set may further include a circuit boardincluding circuits including the tuner; the curved portion of thereflection sheet may be disposed so as to be separated from the cabinet;and the circuit board may be disposed on a lower side of a space betweenthe curved portion and the cabinet.

(51) In the television set as described in Item (47) of the presentinvention, each of the plurality of point light sources may include alight emitting diode and a lens disposed on an outer side of the lightemitting diode.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a cross-sectional view illustrating a basic structure of aliquid crystal display device according to an embodiment mode of thepresent invention;

FIG. 2 is a plan view of a backlight;

FIG. 3 is a view illustrating an arrangement of a plurality of lightemitting diodes of a liquid crystal display device according to a firstembodiment of the present invention;

FIG. 4 is a view illustrating a modified example of the arrangement ofthe plurality of light emitting diodes described in the firstembodiment;

FIG. 5 is a view illustrating an arrangement of a plurality of lightemitting diodes of a liquid crystal display device according to a secondembodiment of the present invention;

FIG. 6 is a view illustrating a modified example of the arrangement ofthe plurality of light emitting diodes described in the secondembodiment;

FIG. 7 is a view illustrating a reflection sheet, which corresponds tothe structure in which the light emitting diodes are arranged asillustrated in FIG. 6;

FIG. 8 is a view illustrating an arrangement of a plurality of lightemitting diodes of a liquid crystal display device according to a thirdembodiment of the present invention;

FIG. 9 is a view illustrating a first modified example of the thirdembodiment;

FIG. 10 is a view illustrating a second modified example of the thirdembodiment;

FIG. 11 is a view illustrating a third modified example of the thirdembodiment;

FIG. 12 is a view illustrating a substrate on which a plurality of lightemitting diodes are mounted in a liquid crystal display device accordingto a fourth embodiment of the present invention;

FIG. 13 is a view illustrating a first modified example of the substratedescribed in the fourth embodiment;

FIG. 14 is a view illustrating a second modified example of thesubstrate described in the fourth embodiment;

FIG. 15 is a view illustrating a substrate on which a plurality of lightemitting diodes are mounted in a liquid crystal display device accordingto a fifth embodiment of the present invention;

FIG. 16 is a view illustrating a substrate on which a plurality of lightemitting diodes are mounted in a liquid crystal display device accordingto a sixth embodiment of the present invention;

FIG. 17 is a view illustrating a first modified example of the substratedescribed in the sixth embodiment;

FIG. 18 is a view illustrating a second modified example of thesubstrate described in the sixth embodiment;

FIG. 19 is a view illustrating a third modified example of the substratedescribed in the sixth embodiment;

FIG. 20 is a view illustrating a fourth modified example of thesubstrate described in the sixth embodiment;

FIG. 21 is a view illustrating a backlight of a liquid crystal displaydevice according to a seventh embodiment of the present invention;

FIG. 22 is a view illustrating a modified example of reflection pieces;

FIG. 23 is a view illustrating another modified example of reflectionpieces;

FIG. 24 is a view illustrating a first modified example of the backlightdescribed in the seventh embodiment;

FIG. 25 is a view illustrating a second modified example of thebacklight described in the seventh embodiment;

FIG. 26 is a view illustrating a third modified example of the backlightdescribed in the seventh embodiment;

FIG. 27 is a view illustrating a fourth modified example of thebacklight described in the seventh embodiment;

FIGS. 28A to 28C are views each illustrating a backlight in a liquidcrystal display device according to an eighth embodiment of the presentinvention;

FIG. 29 is a view illustrating a first modified example of the backlightdescribed in the eighth embodiment;

FIGS. 30A to 30C are views each illustrating a second modified exampleof the backlight described in the eighth embodiment;

FIG. 31 is a view illustrating a third modified example of the backlightdescribed in the eighth embodiment;

FIG. 32 is a view illustrating a fourth modified example of thebacklight described in the eighth embodiment;

FIG. 33 is an exploded perspective view of a liquid crystal televisionset according to a ninth embodiment of the present invention;

FIG. 34 is a view illustrating members provided behind a reflectionsheet of the liquid crystal television set illustrated in FIG. 33;

FIG. 35 is a side view of the liquid crystal television set illustratedin FIG. 33;

FIG. 36 is a schematic view of a vertical cross section of the liquidcrystal television set illustrated in FIG. 33;

FIG. 37 is a graph illustrating a light intensity distribution(directivity characteristic) of a point light source;

FIG. 38 is a graph illustrating a measurement result of intensity oflight;

FIG. 39 is a view illustrating members provided behind a reflectionsheet of a liquid crystal television set according to a tenth embodimentof the present invention; and

FIG. 40 is a schematic view of a vertical cross section of the liquidcrystal television set.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an embodiment mode of the present invention is describedwith reference to the drawings.

Basic Structure

FIG. 1 is a cross-sectional view illustrating a basic structure of aliquid crystal display device according to the embodiment mode of thepresent invention.

The liquid crystal display device includes a liquid crystal displaypanel 10. The liquid crystal display panel 10 has a display surface(left surface in FIG. 1) and a rear surface (right surface in FIG. 1),which is on a side opposite to the display surface. A plurality ofoptical sheets 12, such as a diffusion sheet and a prism sheet, aredisposed so as to be opposed to the rear surface of the liquid crystaldisplay panel 10.

The liquid crystal display device includes a backlight 14. FIG. 2 is aplan view of the backlight 14. The optical sheets 12 are disposedbetween the liquid crystal display panel 10 and the backlight 14. Thebacklight 14 includes a plurality of light emitting diodes 16 serving aslight sources. The plurality of light emitting diodes 16 are mounted ona substrate 18 made of a glass epoxy resin or the like. The substrate 18has a surface on which the plurality of light emitting diodes 16 aremounted, which is opposed to the rear surface (right surface in FIG. 1)of the liquid crystal display panel 10.

A reflection sheet 20 overlaps the substrate 18 at the surface on whichthe plurality of light emitting diodes 16 are mounted in a mannerwithout overlapping the plurality of light emitting diodes 16. Thereflection sheet 20 is larger in size than the substrate 18, and theentire substrate 18 is overlapped with a part of the reflection sheet20. The reflection sheet 20 is made of, for example, a resin. Thereflection sheet 20 is made of a material having a rate of thermalexpansion that is different from that of the material of the substrate18. The reflection sheet 20 has higher light reflectance than thesurface of the substrate 18. As illustrated in FIG. 1, the reflectionsheet 20 is folded or bent so as to avoid being parallel to the rearsurface (right surface in FIG. 1) of the liquid crystal display panel10. In this manner, directions of light beams reflected by thereflection sheet 20 are adjusted.

The substrate 18 on which the light emitting diodes 16 are mounted isattached to a support plate 22. The support plate 22 is fixed to ahousing 24 on an inner side thereof. End portions of the reflectionsheet 20 are attached to the inner side of the housing 24.

The liquid crystal display panel 10 and the substrate 18 each have ashape in which a common width in a first direction D₁ (front-and-reardirection of the sheet plane of FIG. 1 and right-and-left direction inFIG. 2) is longer than a width in a second direction D₂ (up-and-downdirection in FIG. 1 or FIG. 2), which is orthogonal to the firstdirection D₁. For example, each of the liquid crystal display panel 10and the substrate 18 has a rectangular shape which is long in the firstdirection D₁ in plan view.

As illustrated in FIG. 1, a width of the substrate 18 in the seconddirection D₂ is shorter than a width of the liquid crystal display panel10 in the second direction D₂. The width of the substrate 18 in thesecond direction D₂ is one-third the width of the liquid crystal displaypanel 10 in the second direction D₂ or less. The substrate 18 is opposedto, while avoiding being opposed to both end portions of the liquidcrystal display panel 10 in the second direction D₂, a central portionbetween the both end portions of the liquid crystal display panel 10.

According to this embodiment mode, the substrate 18 on which the lightemitting diodes 16 are mounted is small in size, and hence it ispossible to reduce cost and size of the backlight 14.

The contents described above about the basic structure correspond to anyof embodiments described below.

First Embodiment

FIG. 3 is a view illustrating an arrangement of a plurality of lightemitting diodes of a liquid crystal display device according to a firstembodiment of the present invention.

In this embodiment, a plurality of light emitting diodes 116 arearranged in a row in the first direction D₁. Further, pitches betweenadjacent light emitting diodes 116 are equal.

FIG. 4 is a view illustrating a modified example of the arrangement ofthe plurality of light emitting diodes 116 described in the firstembodiment. In this example, the plurality of light emitting diodes 116are arranged at unequal pitches. Specifically, pitches between adjacentlight emitting diodes 116 are smaller as the adjacent light emittingdiodes 116 are closer to a center of a substrate 118 in the firstdirection D₁.

Second Embodiment

FIG. 5 is a view illustrating an arrangement of a plurality of lightemitting diodes of a liquid crystal display device according to a secondembodiment of the present invention.

In this embodiment, a plurality of light emitting diodes 216 arearranged in a staggered (zigzag) pattern in the first direction D₁.Further, pitches between adjacent (obliquely adjacent) light emittingdiodes 216 in an arrangement direction of the staggered pattern areequal.

FIG. 6 is a view illustrating a modified example of the arrangement ofthe plurality of light emitting diodes 216 described in the secondembodiment. In this example, the plurality of light emitting diodes 216are arranged at unequal pitches. For example, pitches between adjacentlight emitting diodes 216 in the arrangement direction of the staggeredpattern are smaller near a center of a substrate 218 in the firstdirection D₁, and are larger near end portions of the substrate 218.

FIG. 7 is a view illustrating a reflection sheet 220, which correspondsto the structure in which the light emitting diodes 216 are arranged asillustrated in FIG. 6. The reflection sheet 220 has a plurality of holes226 formed therein so as to dispose the plurality of light emittingdiodes 216 one by one on the inner side thereof. The plurality of holes226 correspond to the arrangement of the light emitting diodes 216illustrated in FIG. 6, and are arranged in a staggered pattern in thefirst direction D₁. The plurality of holes 226 are arranged at unequalpitches. Specifically, pitches between adjacent holes 226 in thearrangement direction of the staggered pattern are smaller as theadjacent holes 226 are closer to the center of the substrate 218 in thefirst direction D₁.

The reflection sheet 220 has a flat region 228, which is opposed andparallel to the substrate 218 (see FIG. 6). The plurality of holes 226are formed in the flat region 228. The reflection sheet 220 further hasfirst inclined regions 230 provided continuously with the flat region228 in an inclined manner. The first inclined regions 230 arerespectively provided continuously with a pair of sides extending in thefirst direction D₁ of the flat region 228. The reflection sheet 220 isfolded so that boundaries are observable between the flat region 228 andthe first inclined regions 230. In each of the first inclined regions230, a surface on a side opposite to the substrate 218 (surface on whichlight is reflected) is curved so as to become a recess surface.

The reflection sheet 220 further has second inclined regions 232provided continuously with the flat region 228 in an inclined manner.The second inclined regions 232 are respectively provided continuouslywith a pair of sides extending in the second direction D₂ of the flatregion 228. The reflection sheet 220 is folded so that boundaries areobservable between the flat region 228 and the second inclined regions232. One second inclined region 232 is positioned between a pair of thefirst inclined regions 230, and one first inclined region 230 ispositioned between a pair of the second inclined regions 232.

Third Embodiment

FIG. 8 is a view illustrating an arrangement of a plurality of lightemitting diodes of a liquid crystal display device according to a thirdembodiment of the present invention.

In this embodiment, a plurality of light emitting diodes 316 areseparated into a first group and a second group. Light emitting diodes316 a in the first group are arranged in a row in the first directionD₁. The light emitting diodes 316 a in the first group are disposed atboth end portions of a substrate 318, which sandwich a central portionthereof. The light emitting diodes 316 a in the first group are arrangedat equal pitches in the first direction D₁.

Light emitting diodes 316 b in the second group are arranged in astaggered pattern in the first direction D₁. The light emitting diodes316 b in the second group are disposed at the central portion in thefirst direction D₁ of the substrate 318. The light emitting diodes 316 bin the second group are arranged at equal pitches in the arrangementdirection of the staggered pattern.

FIG. 9 is a view illustrating a first modified example of the thirdembodiment. In a substrate 320 of this example, a width of a centralportion 320 b in the second direction D₂ is larger than a width of eachend portion 320 a in the second direction D₂. This is the pointdifferent from the substrate 318 illustrated in FIG. 8.

FIG. 10 is a view illustrating a second modified example of the thirdembodiment. In this example, pitches between adjacent light emittingdiodes 316 c in the first group are smaller as the adjacent lightemitting diodes 316 c are closer to a center of the substrate 318 in thefirst direction D₁. Further, pitches between adjacent light emittingdiodes 316 d in the second group in the arrangement direction of thestaggered pattern are smaller as the adjacent light emitting diodes 316d are closer to the center of the substrate 318 in the first directionD₁.

FIG. 11 is a view illustrating a third modified example of the thirdembodiment. In a substrate 320 of this example, a width of the centralportion 320 b in the second direction D₂ is larger than a width of eachend portion 320 a in the second direction D₂. This is the pointdifferent from the substrate 318 illustrated in FIG. 10. cl FourthEmbodiment

FIG. 12 is a view illustrating a substrate on which a plurality of lightemitting diodes are mounted in a liquid crystal display device accordingto a fourth embodiment of the present invention.

In this embodiment, pitches between adjacent light emitting diodes 416are smaller as the adjacent light emitting diodes 416 are closer to acenter of a substrate 418 in the first direction D₁. Further, thesubstrate 418 is divided into a first divided substrate 438 and a seconddivided substrate 440 between adjacent light emitting diodes 416 havingthe smallest pitch. The first divided substrate 438 and the seconddivided substrate 440 have the same design, and have a positionalrelationship of rotation symmetry to each other. The rotation center ofthe rotation symmetry in this case is positioned between the firstdivided substrate 438 and the second divided substrate 440.

At least one of the first divided substrate 438 and the second dividedsubstrate 440 (both in the example of FIG. 12) includes, at one endportion thereof, a cable connector 436 for connection to a cable 434.Further, the first divided substrate 438 and the second dividedsubstrate 440 are disposed so that the other end portion of the firstdivided substrate 438 and the other end portion of the second dividedsubstrate 440 are adjacent to each other.

FIG. 13 is a view illustrating a first modified example of the substrate418 described in the fourth embodiment. In this example, end portions ofa first divided substrate 446 and a second divided substrate 448, theend portions being adjacent to each other, each have a recess portion442 and a convex portion 444 at surfaces which are opposed to eachother. The first divided substrate 446 and the second divided substrate448 are disposed so that the recess portion 442 of one divided substrateis opposed to the convex portion 444 of the other divided substrate.

The plurality of light emitting diodes 416 are arranged in a staggeredpattern in the first direction D₁ at least on the end portion side ofthe first divided substrate 446, at which the recess portion 442 and theconvex portion 444 are formed, and on the end portion side of the seconddivided substrate 448, at which the recess portion 442 and the convexportion 444 are formed. Specifically, each of the first dividedsubstrate 446 and the second divided substrate 448 includes a wideportion 450 and a narrow portion 452 in width in a short side direction,and in the wide portion 450, the plurality of light emitting diodes 416are arranged in a staggered pattern. The convex portion 444 is protrudedin the first direction D₁ from a light emitting diode 416 positionedoutermost in the first direction D₁ of each of the first dividedsubstrate 446 and the second divided substrate 448. The convex portion444 and the recess portion 442 are formed adjacent to each other, and aside distinguishing the two portions extends so as to be parallel to thefirst direction D₁.

FIG. 14 is a view illustrating a second modified example of thesubstrate 418 described in the fourth embodiment. In this example,across an entire first divided substrate 454 and an entire seconddivided substrate 456, the plurality of light emitting diodes 416 arearranged in a staggered pattern in the first direction D₁. Therefore,each of the first divided substrate 454 and the second divided substrate456 has a constant width in the short side direction, which is differentfrom the example of FIG. 13. In FIG. 14, a side 458 distinguishing theconvex portion and the recess portion extends obliquely so as tointersect the first direction D₁.

Fifth Embodiment

FIG. 15 is a view illustrating a substrate on which a plurality of lightemitting diodes are mounted in a liquid crystal display device accordingto a fifth embodiment of the present invention.

In this embodiment, pitches between adjacent light emitting diodes 516are smaller as the adjacent light emitting diodes 516 are closer to acenter of a substrate 518 in the first direction D₁. The substrate 518is divided into a first divided substrate 538 and a second dividedsubstrate 540 between adjacent light emitting diodes 516 provided at aposition away from a position where adjacent light emitting diodes 516having the smallest pitch are provided. At least one of the firstdivided substrate 538 and the second divided substrate 540 (both in theexample of FIG. 15) includes, at one end portion thereof, a cableconnector 536 for connection to a cable 534. The first divided substrate538 and the second divided substrate 540 are disposed so that the otherend portion of the first divided substrate 538 and the other end portionof the second divided substrate 540 are adjacent to each other.

Sixth Embodiment

FIG. 16 is a view illustrating a substrate on which a plurality of lightemitting diodes are mounted in a liquid crystal display device accordingto a sixth embodiment of the present invention.

In this embodiment, pitches between adjacent light emitting diodes 616are smaller as the adjacent light emitting diodes 616 are closer to acenter of a substrate 618 in the first direction D₁. The substrate 618is divided into a first divided substrate 638, a second dividedsubstrate 640, and a third divided substrate 646 between adjacent lightemitting diodes 616 provided at positions away from a position whereadjacent light emitting diodes 616 having the smallest pitch areprovided.

At one end portion of the first divided substrate 638, a cable connector636 for connection to a cable 634 is provided. The other end portion ofthe first divided substrate 638 and one end portion of the seconddivided substrate 640 are electrically connected to each other by afirst substrate connector 648. The other end portion of the seconddivided substrate 640 and one end portion of the third divided substrate646 are electrically connected to each other by a second substrateconnector 650.

FIG. 17 is a view illustrating a first modified example of the substrate618 described in the sixth embodiment. In this example, the plurality oflight emitting diodes 616 are arranged in a staggered pattern in thefirst direction D₁. Pitches between adjacent light emitting diodes 616correspond to pitches between adjacent light emitting diodes 616 in anarrangement direction of the staggered pattern.

FIG. 18 is a view illustrating a second modified example of thesubstrate 618 described in the sixth embodiment. In this example, endportions of a first divided substrate 652 and a second divided substrate654, the end portions being electrically connected to each other, eachhave a recess portion 642 and a convex portion 644 at surfaces which areopposed to each other. End portions of the second divided substrate 654and a third divided substrate 656, the end portions electricallyconnected to each other, each have the recess portion 642 and the convexportion 644 at surfaces which are opposed to each other.

The convex portion 644 is protruded in the first direction D₁ from alight emitting diode 616 positioned outermost in the first direction D₁of each of the first divided substrate 652, the second divided substrate654, and the third divided substrate 656.

The first divided substrate 652 and the second divided substrate 654 aredisposed so that the recess portion 642 of one divided substrate isopposed to the convex portion 644 of the other divided substrate. Thesecond divided substrate 654 and the third divided substrate 656 aredisposed so that the recess portion 642 of one divided substrate isopposed to the convex portion 644 of the other divided substrate.

FIG. 19 is a view illustrating a third modified example of the substrate618 described in the sixth embodiment. In this example, light emittingdiodes 616 disposed on a second divided substrate 660 are arranged in astaggered pattern in the first direction D₁. Pitches between adjacentlight emitting diodes 616 correspond to pitches between adjacent lightemitting diodes 616 in an arrangement direction of the staggeredpattern. Meanwhile, light emitting diodes 616 respectively disposed on afirst divided substrate 658 and a third divided substrate 662 arearranged in a row in the first direction D₁.

FIG. 20 is a view illustrating a fourth modified example of thesubstrate 618 described in the sixth embodiment. In this example, awidth of a second divided substrate 666 in the second direction D₂ islarger than any of a width of a first divided substrate 664 in thesecond direction D₂ and a width of a third divided substrate 668 in thesecond direction D₂.

Seventh Embodiment

FIG. 21 is a view illustrating a backlight of a liquid crystal displaydevice according to a seventh embodiment of the present invention.

In this embodiment, light emitting diodes 716 are arranged in astaggered pattern in the first direction D₁. A backlight 714 includes afirst reflection sheet 778, which overlaps a substrate 718. The firstreflection sheet 778 has a plurality of first holes 752 formed therein,which allow the plurality of light emitting diodes 716 to be disposed onthe inner side thereof.

The backlight 714 includes a second reflection sheet 772 adhered to thesubstrate 718. The second reflection sheet 772 is divided into aplurality of reflection pieces 758. The second reflection sheet 772includes, as a whole, a plurality of second holes 754, which allow theplurality of light emitting diodes 716 to be respectively disposed onthe inner side thereof. One reflection piece 758 includes one secondhole 754, which allows one light emitting diode 716 to be disposed onthe inner side thereof. On the inner side of each of the first holes752, at least a part of an edge portion of the corresponding second hole754 is exposed. That is, the first reflection sheet 778 overlaps thesecond reflection sheet 772 (plurality of reflection pieces 758) adheredto substrate 718.

Pitches between adjacent light emitting diodes 716 are smaller as theadjacent light emitting diodes 716 are closer to a center of thesubstrate 718 in the first direction D₁. Further, the plurality ofreflection pieces 758 are each formed in a size and shape so that, at aposition corresponding to the adjacent light emitting diodes 716 havingthe smallest pitch, adjacent reflection pieces 758 are provided withoutoverlapping each other.

The reflection pieces 758 illustrated in FIG. 21 each have a rectangularouter shape, but alternatively, there may be used reflection pieces 724each having a hexagonal outer shape as illustrated in FIG. 22, orreflection pieces 726 each having a circular outer shape as illustratedin FIG. 23.

FIG. 24 is a view illustrating a first modified example of the backlightdescribed in the seventh embodiment. In this example, pitches betweenadjacent light emitting diodes 716 are smaller as the adjacent lightemitting diodes 716 are closer to the center of the substrate 718 in thefirst direction D₁. A second reflection sheet 732 is divided into afirst reflection piece 762 and a plurality of second reflection pieces764. The first reflection piece 762 is disposed in a first region 756 atthe center of the substrate 718. The first reflection piece 762 includesat least two second holes 754. The plurality of second reflection pieces764 are disposed at a pair of second regions 760 of the substrate 718,which sandwich the first region 756. Each of the second reflectionpieces 764 includes one second hole 754.

FIG. 25 is a view illustrating a second modified example of thebacklight described in the seventh embodiment. In this example, a firstreflection piece 782 includes at least two second holes 784. Each secondreflection piece 786 includes at least two second holes 788. Othercontents correspond to the contents of the first modified exampledescribed above.

FIG. 26 is a view illustrating a third modified example of the backlightdescribed in the seventh embodiment. In this example, the light emittingdiodes 716 disposed in each second region 790 are arranged in a row inthe first direction D₁.

FIG. 27 is a view illustrating a fourth modified example of thebacklight described in the seventh embodiment. In this example, a secondreflection sheet 792 is divided into a plurality of reflection pieces794. Each of the reflection pieces 794 includes at least two secondholes 796, which allow at least two light emitting diodes 716 to bedisposed on the inner side thereof one by one. A substrate 798 isdivided into a plurality of divided substrates 800. Each of thereflection pieces 794 has an outer shape which is similar to that of thedivided substrate 800 to which the corresponding reflection piece isadhered.

Eighth Embodiment

FIG. 28A is a view illustrating a backlight in a liquid crystal displaydevice according to an eighth embodiment of the present invention.

In this embodiment, above a substrate 818 and above at least one lightemitting diode 816, a lens 866 is disposed. The substrate 818 issupported by a support plate 822 on a side opposite to the plurality oflight emitting diodes 816. The support plate 822 is larger in size thanthe substrate 818.

The lens 866 is attached to the support plate 822 on the outer side ofthe substrate 818. For example, the lens 866 is adhered to the supportplate 822 by an adhesive 868. The adhesive 868 may be provided at threeportions arranged every 120 degrees in a circumferential direction asillustrated in FIG. 28A, at two portions arranged every 180 degrees inthe circumferential direction as illustrated in FIG. 28B, or at fourportions arranged every 90 degrees in the circumferential direction asillustrated in FIG. 28C.

FIG. 29 is a view illustrating a first modified example of the backlightdescribed in the eighth embodiment. In this example, a spacer 870 isprovided on the support plate 822, and the lens 866 is supported by thesupport plate 822 through intermediation of the spacer 870.

FIG. 30A is a view illustrating a second modified example of thebacklight described in the eighth embodiment. In this example, aplurality of substrates 818 are supported by the support plate 822,which is larger in size than the substrate 818, on the side opposite tothe plurality of light emitting diodes 816. Above each of the substrates818 and above at least one light emitting diode 816, the lens 866 isdisposed. The lens 866 is attached to the support plate 822 on the outerside of the substrate 818 disposed below the lens 866.

The lens 866 is attached to the support plate 822 on the outer side ofthe substrate 818. For example, the lens 866 is adhered to the supportplate 822 by the adhesive 868. The adhesive 868 may be provided at threeportions arranged every 120 degrees in the circumferential direction asillustrated in FIG. 30A, at two portions arranged every 180 degrees inthe circumferential direction as illustrated in FIG. 30B, or at fourportions arranged every 90 degrees in the circumferential direction asillustrated in FIG. 30C.

FIG. 31 is a view illustrating a third modified example of the backlightdescribed in the eighth embodiment. In this example, a spacer 880 isprovided on the support plate 822. The lens 866 is supported by thesupport plate 822 through intermediation of the spacer 880. The spacer880 is disposed at least without being divided between the adjacentsubstrates 818. Both of the lenses 866, which are positioned above onesubstrate 818 and the other substrate 818, respectively, are supportedby the spacer 880 disposed between the adjacent substrates 818.

FIG. 32 is a view illustrating a fourth modified example of thebacklight described in the eighth embodiment. In this example, a spacer890 is divided into a first divided spacer 892 and a second dividedspacer 894. Between the adjacent substrates 818, the first dividedspacer 892 is disposed near one substrate 818, and the second dividedspacer 894 is disposed near the other substrate 818. The lens 866positioned above the one substrate 818 is supported by the first dividedspacer 892. The lens 866 positioned above the other substrate 818 issupported by the second divided spacer 894.

By incorporating the liquid crystal display device described in any oneof the embodiments described above, a television set can be formed,which receives radio waves for television broadcast to display imagesand output sound. Hereinafter, a liquid crystal television set isdescribed as an example.

Ninth Embodiment

FIG. 33 is an exploded perspective view of a liquid crystal televisionset according to a ninth embodiment of the present invention. FIG. 34 isa view illustrating members provided behind a reflection sheet of theliquid crystal television set illustrated in FIG. 33. FIG. 35 is a sideview of the liquid crystal television set illustrated in FIG. 33. FIG.36 is a schematic view of a vertical cross section of the liquid crystaltelevision set illustrated in FIG. 33.

The liquid crystal television set includes a liquid crystal displaypanel 900 having a horizontally long screen. The screen of the liquidcrystal television set has an aspect ratio (ratio of horizontaldimension to vertical dimension) of 16:9. The liquid crystal displaypanel 900 has a front side (side on which an image is displayed)supported by an upper frame 902, and a rear side supported by a moldframe 904. The liquid crystal television set includes a backlight 906,which is overlapped by the liquid crystal display panel 900.

The liquid crystal display panel 900, the upper frame 902, the moldframe 904, and the backlight 906 are stored in a cabinet 912 including afront cabinet 908 and a back cabinet 910. The front cabinet 908 is madeof a resin, and the back cabinet 910 is made of a metal subjected tocoating or a resin. The cabinet 912 is supported by a stand 918including a pedestal 914 and a leg 916. As illustrated in FIG. 35, onthe side surface of the cabinet 912, switches 920 for selecting achannel to be displayed and controlling the volume are provided.

A cover 922 is attached to a lower rear part of the back cabinet 910. Aspeaker 924 and a circuit board 926 are disposed inside the cover 922.The circuit board 926 includes a tuned circuit (tuner) for selecting aradio wave having a specific frequency from radio waves having variousfrequencies.

The backlight 906 includes a reflection sheet 930 having a curvedportion 928 so that a recess surface thereof faces the liquid crystaldisplay panel 900. The curved portion 928 of the reflection sheet 930 isdisposed so as to be separated from the cabinet 912 (see FIG. 36). Thecurved portion 928 includes a first curved portion 932 and a secondcurved portion 934. The first curved portion 932 and the second curvedportion 934 are formed on respective sides of the reflection sheet 930in a vertical direction of the screen while sandwiching a plurality ofpoint light sources 936. The circuit board 926 is disposed on a lowerside of a space between the curved portion 928 and the back cabinet 910(see FIG. 36).

The backlight 906 includes a substrate 938 on which the reflection sheet930 is overlapped on a side opposite to the liquid crystal display panel900 of the reflection sheet 930. A width of the substrate 938 in thevertical direction of the screen is half the length of the screen in thevertical direction or less. The substrate 938 is fixed to the cabinet912. The substrate 938 may be directly fixed to the cabinet 912, or maybe fixed to the cabinet 912 through intermediation of a radiator plate940. FIG. 33 exemplifies the latter case, that is, the substrate 938 isfixed to the radiator plate 940, and the radiator plate 940 is fixed tothe cabinet 912. Note that, the substrate 938 and the radiator plate 940correspond to the substrate 18 and the support plate 22 of FIG. 1,respectively.

In this embodiment, at a position roughly corresponding to a center ofthe screen, the point light sources 936 including light emitting diodes942 (see FIG. 36) are mounted on the rectangular substrate 938, which islong in the horizontal direction. A printed-wiring board may be used asthe substrate 938. Fixation of the substrate 938 is performed bythreadably mounting the substrate 938 on the back cabinet 910, orthreadably mounting the substrate 938 on the radiator plate 940 made ofa metal such as aluminum and then fixing the radiator plate 940 to theback cabinet 910. The light emitting diodes 942 are arranged in astaggered pattern and in two rows in the up-and-down direction, so as toextend in the horizontal direction. When seen from the front side, adimension YL of the substrate 938 is set so as to be one-third a heightYH of the screen of the liquid crystal display panel 900 or less.

The backlight 906 includes the plurality of point light sources 936,which are mounted on the substrate 938 and disposed so as to protrude tothe recess surface side of the curved portion 928 while passing throughthe reflection sheet 930. The plurality of point light sources 936 arearranged in at least one row in the horizontal direction of the screen,and arranged so as to be stored within a space region, which has a widthin the vertical direction of the screen, the width being half the lengthof the screen in the vertical direction or less. Each of the point lightsources 936 includes, as illustrated in FIG. 36, the light emittingdiode 942 and a lens 944 disposed on the outer side thereof. On thesubstrate 938, the lenses 944 each made using an acrylic resin aremounted so as to respectively cover the light emitting diodes 942.

The point light source 936 emits light in a perpendicular direction tothe substrate 938 and in other directions, and light emitted in theother directions is higher in intensity than light emitted in theperpendicular direction. The lens 944 has a wide light distributioncharacteristic, which causes the light emitted from the light emittingdiode 942 to be more spread out in a viewing angle direction than in afront side direction. Such a light intensity distribution (directivitycharacteristic) of the point light source 936 is illustrated in FIG. 37.Further, FIG. 38 is a graph illustrating a measurement result ofintensity of light which exits from the lens 944. Note that, anglevalues represent a light emission direction from the point light source936. 0° corresponds to the surface side opposed to the liquid crystaldisplay panel 900 (vertical direction to a plane of the substrate 938),and ±90° correspond to directions parallel to the plane of the substrate938.

One of the features of the liquid crystal television set is high imagequality performance, which provides an impression that, although thevertical direction dimension YL of the substrate 938 is reduced to beone-third the screen dimension YH or less along the vertical directionof the screen, the screen is bright and high brightness uniformity isprovided across the entire screen.

In the conventional liquid crystal television set, a plurality ofsubstrates each including a plurality of light emitting diodes areprovided so as to obtain uniform brightness or smooth brightness changeeven in a region between the substrates. Specifically, many lightemitting diodes are used to shorten intervals between the light emittingdiodes and hence obtain smooth brightness change, and the substrates aredisposed so that each position of the individual light emitting diodescannot be optically recognized. Further, there is a case where wideintervals are provided between the plurality of substrates by disposinglenses for wide light distribution above the light emitting diodes, buteven in this case, the dimension of the substrates is larger than halfthe screen.

In this embodiment, a dimension between outer surfaces of a pair oflenses 944 which are most separated in the vertical direction, the outersurfaces facing directions opposite to each other, is one-third thescreen dimension YH or less. When the light emitting diodes 942 arearranged in a row in the horizontal direction, a width (diameter) of thelens 944 in the vertical direction is one-third the screen dimension YHor less. In order to reduce cost, the light emitting diode 942 and thelens 944 are formed in dimensions not to extend off the substrate 938,and the dimensions thereof are set to the minimum.

In this embodiment, the vertical dimension YL of the substrate 938, orthe dimension between outer sides of the lenses 944 arranged in two rowsin the vertical direction, is one-third the vertical dimension of thescreen or less. Therefore, even if the number of the light emittingdiodes 942 is reduced, the screen is bright and a natural and smoothbrightness distribution is obtained. Therefore, the cost may be greatlyreduced.

In this embodiment, the curved portion 928 of the reflection sheet 930is formed so as to have a width of a length obtained by subtracting thevertical dimension YL of the substrate 938 from the dimension YH in thevertical direction of the screen (short side direction of the screen).When the width of the curved portion 928 is half the dimension YH ormore, the brightness distribution of the screen is comfortable even whenthe screen is seen from the front side. Further, the number of lightemitting diodes 942 may be significantly reduced, and hence the cost maybe reduced. That is, the cost may be reduced by forming a region forreflection by the curved portion 928 to be larger than a region for aspace where the point light sources 936 are stored.

The light emitted from the light emitting diode 942 disposed on thesubstrate 938 is spread out by the lens 944, which is made of an acrylicresin and disposed above the light emitting diode 942. The light thusspread out has a distribution characteristic that light intensity islarger in an oblique direction than in the front side direction. Thelens 944 for wide light distribution is attached to each of theplurality of light emitting diodes 942, and hence, in a space in a rangefrom the substrate 938 to a diffusion plate 946 provided in theperpendicular direction (direction to the screen) (hereinafter, referredto as inner thickness Zd), the light radiated to a peripheral directionof the screen from the substrate 938 has higher light intensity thanthat of the light emitted to the front side. Part of the light whichexits from the lens 944 to the front side passes through the diffusionplate 946, and then is used to display an image by the liquid crystaldisplay panel 900. Further, part of the light is reflected by thediffusion plate 946, and then reflected by the reflection sheet 930, tothereby be radiated to a direction different from the front sidedirection. Further, other part of light may directly enter thereflection sheet 930 from the lens 944, to thereby be radiated tovarious directions. The light which exits from the lens 944 isrepeatedly reflected in the space between the reflection sheet 930having the curved portion 928 and the diffusion plate 946, and thuslight is caused to pass through almost the entire region of the screenwith the use of the diffusion plate 946.

As for the brightness performance of the liquid crystal television sethaving the above-mentioned structure, when the maximum brightnessmeasured from the front side is 100%, the periphery thereof is in a darkstate of about 30%. A ratio of the brightness at the center of thescreen in the front side to the average brightness is 1.65. However,because the curved portion 928 of the reflection sheet 930 is smoothlycurved, smooth brightness change is obtained from the substrate 938 inthe vertical direction of the screen. Therefore, even though the ratioof the central brightness to the average brightness is as large as 1.65,it is possible to provide a comfortable image because a large inflectionpoint is absent in the distribution thereof.

The fact that a comfortable and smooth brightness distribution can beobtained even though the ratio of the central brightness to the averagebrightness is 1.65 or larger represents that, conversely, it is possibleto reduce the number of the light emitting diodes 942 and narrow thewidth of the substrate 938, to thereby reduce the cost.

Note that, it is impossible to achieve the characteristic that thebrightness at the center is high and the brightness decreases withsmooth brightness distribution toward the periphery of the screen when astructure which blocks light radiation to the front side is provided. Inthis case, the center is dark, which results in uncomfortable displaydistribution. Therefore, the light emission characteristic of each pointlight source 936, which includes the light emitting diode 942 and thelens 944 near the corresponding light emitting diode 942, includes apredetermined output to the front side.

The back cabinet 910 forms the outermost surface of the liquid crystaltelevision set. The substrate 938 is threadably mounted on the radiatorplate 940. By dissipating the heat from the light emitting diodes 942 bythe substrate 938 and the radiator plate 940, the junction temperatureof the light emitting diode 942 is suppressed to a predetermined value.In a case where the specification brightness of the liquid crystaltelevision set is low, the radiator plate 940 may be omitted. In thiscase, the substrate 938 is directly fixed to the back cabinet 910. Inthis case, heat dissipation of the light emitting diode 942 is performedonly by the substrate 938, but even with the heat dissipation effect ofthe substrate 938, the junction temperature of the light emitting diode942 may be suppressed to a predetermined value.

The substrate 938 and the reflection sheet 930 are fixed at positionsnear the back cabinet 910, and hence it is possible to achieve a thinliquid crystal television set. With this structure, the thickness of theliquid crystal television set may be reduced while maintaining thecomfortable uniformity of the brightness performance.

In the conventional backlight structure, the substrate on which thelight emitting diodes are mounted is fixed to a back frame (not shown)of the liquid crystal display device, which is made of iron or aluminum.On the outer portion of the back frame, there are disposed a powersupply for driving the light emitting diodes and a substrate of a timingcontroller for controlling a gate signal line and a drain signal line ofthe liquid crystal display panel. The back cabinet of the television setis disposed on a further outer portion thereof. Therefore, thetelevision set requires, in addition to the inner thickness distancebetween the diffusion plate and the light emitting diode of thebacklight, a distance provided between the back frame and the backcabinet, which causes the liquid crystal television set to be thick.

In this embodiment, light, which exits from the lens 944 with a higherbrightness in the periphery than in the front side, passes through thepredetermined space (inner thickness Zd), and then passes through thediffusion plate 946 and the liquid crystal display panel 900. With this,an image is displayed. The substrate 938 is brought into contact withthe radiator plate 940, and the radiator plate 940 and the back cabinet910 are fixed to each other by a screw, and hence a space distance otherthan the inner thickness Zd is unnecessary. Therefore, the thickness ofthe liquid crystal television set may be reduced.

The reduction in thickness of the liquid crystal television set isachieved also by the disposition of the circuit board 926 including apower supply circuit, a video circuit, a tuned circuit (tuner), and atiming circuit for the liquid crystal display panel 900. Specifically,the curved portion 928 of the reflection sheet 930 is curved in adirection separating from the back cabinet 910, and hence a large spacecan be obtained between the curved portion 928 and the back cabinet 910.In the lower portion of the liquid crystal television set, the circuitboard 926 including the power supply circuit, the video circuit, thetuned circuit (tuner), and the timing circuit for the liquid crystaldisplay panel 900 is stored in a compact manner. With this, a space isunnecessary between the back cabinet 910 and the substrate 938 on whichthe light emitting diodes 942 are mounted or the radiator plate 940.With this structure, even though the curved reflection sheet 930 isused, it is possible to achieve a thin television set.

Next, manufacturing steps of the liquid crystal television set aredescribed with reference to FIGS. 33 to 36. For example, a wall-mountbracket 948 is attached to the back cabinet 910 from the inner sidethereof, the back cabinet 910 being formed by subjecting a member madeof an iron material to coating. The wall-mount bracket 948 reinforcesthe strength of the back cabinet 910. Screw receiving holes are formedin the wall-mount bracket 948, which are used when the liquid crystaltelevision set is mounted on the wall from the rear side of the backcabinet 910. The radiator plate 940 is fixed to the inner side of theback cabinet 910, the radiator plate being made of, for example, analuminum material.

Next, the substrate 938 on which the light emitting diodes 942 aremounted is attached to the radiator plate 940. On each of the lightemitting diodes 942, the acrylic lens 944 for wide light distribution iscapped, and the lens 944 is fixed by an adhesive. Depending on thebrightness specification of the liquid crystal television set, whenthere is a margin in the junction temperature of the light emittingdiode 942, the substrate 938 may be directly attached to the backcabinet 910. Here, on the surface of the substrate 938, a reflectionsheet, such as the second reflection sheet 772 of the seventhembodiment, is adhered to the periphery of the light emitting diodes942. Instead of a sheet such as the second reflection sheet 772, a whiteresist may be applied onto the substrate 938 so that light emitted fromthe light emitting diodes 942 can easily perform successive reflection.

A connector 950 illustrated in FIG. 34 is an electrical connectionportion of wiring lines extending to the point light sources 936 on thesubstrate 938. A wiring line 951 is connected to the connector 950, andis pulled out to the rear surface of the back cabinet 910 via anextraction hole 952 formed in the back cabinet 910 to be connected tothe circuit board 926 (see FIG. 36). The circuit board 926 includes aninverter circuit for controlling the light emitting diodes 942. Further,the extraction hole 952 is opened at a position overlapped with thecover 922 described later. With this, dust and the like are preventedfrom entering the back cabinet 910 from the outside.

Next, the reflection sheet 930 is attached, which has a surface withlight diffusion property, is curved in the vertical direction of thescreen, and has holes larger in diameter than the lens 944 so as toinsert the lenses 944 therethrough. Above the reflection sheet 930, thediffusion plate 946, a prism sheet 953, and a diffusion sheet 955, eachhaving a thickness of 1.5 mm to 3 mm, are disposed. In the space (innerthickness Zd) between the substrate 938 and the rear surface of thediffusion plate 946, direct light from the light emitting diodes 942 andreflected light, which is secondary light, from the reflection sheet 930are combined.

Next, the optical sheet group is fixed by the mold frame 904, which ismade of a resin material and divided in quarters. Above the mold frame904, the liquid crystal display panel 900 is disposed. The liquidcrystal display panel 900 includes two glass substrates and liquidcrystal sealed therebetween. One substrate (TFT substrate) includes thinfilm transistors (TFTs), drain signal lines, and gate signal lines, andthe other substrate includes a color filter. The gate signal lines andthe drain signal lines formed on the TFT substrate are pulled outside tobe connected to a driver IC and a drain substrate on which the driver ICis mounted. On each surface of the glass substrates, a polarizing plateis adhered. The drain substrate is electrically connected to the timingcontrol circuit for supplying the video signal via a flexible cable.Above the liquid crystal display panel 900, the upper frame 902 made ofiron is attached, for blocking electromagnetic waves from the driver ICand fixing the liquid crystal display panel 900.

In order to finally complete the liquid crystal television set, thefront cabinet 908 made of a resin material is attached to the surface ofthe upper frame 902. On the lower side of the cabinet 912, a controlcircuit for the light emitting diodes 942, a timing control circuit, apower supply circuit for supplying power to the video circuit, aconnection terminal to the outside, and the like are disposed, and thecover 922 for protection, which is made of a resin, is attached.

Note that, in this embodiment, an example using the wall-mount bracket948 is described, but when the back cabinet 910 is strong enough, thewall-mount bracket 948 may be omitted.

Tenth Embodiment

FIG. 39 is a view illustrating members provided behind a reflectionsheet of a liquid crystal television set according to a tenth embodimentof the present invention. FIG. 40 is a schematic view of a verticalcross section of the liquid crystal television set.

The liquid crystal television set according to this embodiment is largerin screen size than the liquid crystal television set of the ninthembodiment. Therefore, when all light emitting diodes 972 are mounted onone substrate, the substrate size increases, and therefore the costincreases. Therefore, in this embodiment, the substrate is divided intoa plurality of parts. That is, a substrate 960 includes a plurality ofdivided substrates 962 arranged in the vertical direction of the screen.

Each of the plurality of divided substrates 962 includes light emittingdiodes 972 mounted thereon, and adjacent divided substrates 962 has aninterval provided therebetween so that an interval between the centerpoints of the light emitting diodes 972 is YYL. The plurality of dividedsubstrates 962 are fixed to a radiator plate 970. The dimension YYL isincreased to a distance that unevenness does not occur in the verticaldirection in the light distribution of the point light sources 964.Further, the liquid crystal television set of this embodiment does notmount the wall-mount bracket.

The width YL in the vertical direction of the space region where theplurality of point light sources 964 are stored is smaller than adistance obtained by subtracting the width YL from the verticaldimension of the screen, that is, a width in the vertical direction ofthe curved portion 968 of the reflection sheet 966. With this, there maybe obtained a brightness distribution in which the brightness on thefront side is high and the brightness smoothly decreases toward theperiphery of the screen. In this distribution, brightness is lower atthe periphery, but a comfortable brightness distribution is observedwhen seen from the front side. Therefore, it is possible to reduce thetotal light amount necessary for the liquid crystal television set, andhence the cost can be reduced.

As described above, in this embodiment, it is possible to reduce thecost of the liquid crystal television set having a screen larger thanthat of the ninth embodiment. Other contents of this embodimentcorrespond to the contents described in the ninth embodiment.

The present invention is not limited to the embodiments described above,and various modifications may be made thereto. For example, thestructures described in the embodiments may be replaced by substantiallythe same structure, a structure having the same action and effect, and astructure which may achieve the same object.

What is claimed is:
 1. A liquid crystal display device, comprising: aliquid crystal display panel having a display surface and a rearsurface, which is on a side opposite to the display surface; and abacklight, wherein: the backlight comprises: a plurality of lightemitting diodes; a substrate on which the plurality of light emittingdiodes are mounted; and a reflection sheet, which overlaps the substrateat a surface on which the plurality of light emitting diodes are mountedin a manner without overlapping the plurality of light emitting diodes;the surface on which the plurality of light emitting diodes are mountedof the substrate is opposed to the rear surface of the liquid crystaldisplay panel; the liquid crystal display panel and the substrate eachhave a shape in which a common width in a first direction is longer thana width in a second direction, which is orthogonal to the firstdirection; the width of the substrate in the second direction is shorterthan the width of the liquid crystal display panel in the seconddirection, the substrate being opposed to, while avoiding being opposedto both end portions of the liquid crystal display panel in the seconddirection, a central portion between the both end portions of the liquidcrystal display panel; pitches between adjacent light emitting diodes ofthe plurality of light emitting diodes are smaller as the adjacent lightemitting diodes are closer to a center of the substrate in the firstdirection; the substrate is divided into a first divided substrate and asecond divided substrate between adjacent light emitting diodes having asmallest pitch among the pitches; at least one of the first dividedsubstrate and the second divided substrate includes, at one end portionof the at least one of the first divided substrate and the seconddivided substrate, a cable connector for connection to a cable; and thefirst divided substrate and the second divided substrate are disposed sothat another end portion of the first divided substrate and another endportion of the second divided substrate are adjacent to each other. 2.The liquid crystal display device according to claim 1, wherein thefirst divided substrate and the second divided substrate have the samedesign, and have a positional relationship of rotation symmetry to eachother.
 3. The liquid crystal display device according to claim 2,wherein: the another end portion of the first divided substrate and theanother end portion of the second divided substrate each have a recessportion and a convex portion at surfaces which are opposed to eachother; and the first divided substrate and the second divided substrateare disposed so that the recess portion of one divided substrate isopposed to the convex portion of another divided substrate.
 4. Theliquid crystal display device according to claim 3, wherein: theplurality of light emitting diodes are arranged in a staggered patternin the first direction at least on the another end portion side of thefirst divided substrate, at which the recess portion and the convexportion are formed, and on the another end portion side of the seconddivided substrate, at which the recess portion and the convex portionare formed; and the convex portion is protruded in the first directionfrom one of the plurality of light emitting diodes, which is positionedoutermost in the first direction of each of the first divided substrateand the second divided substrate.
 5. A liquid crystal display device,comprising: a liquid crystal display panel having a display surface anda rear surface, which is on a side opposite to the display surface; anda backlight, wherein: the backlight comprises: a plurality of lightemitting diodes; a substrate on which the plurality of light emittingdiodes are mounted; and a reflection sheet, which overlaps the substrateat a surface on which the plurality of light emitting diodes are mountedin a manner without overlapping the plurality of light emitting diodes;the surface on which the plurality of light emitting diodes are mountedof the substrate is opposed to the rear surface of the liquid crystaldisplay panel; the liquid crystal display panel and the substrate eachhave a shape in which a common width in a first direction is longer thana width in a second direction, which is orthogonal to the firstdirection; the width of the substrate in the second direction is shorterthan the width of the liquid crystal display panel in the seconddirection, the substrate being opposed to, while avoiding being opposedto both end portions of the liquid crystal display panel in the seconddirection, a central portion between the both end portions of the liquidcrystal display panel; pitches between adjacent light emitting diodes ofthe plurality of light emitting diodes are smaller as the adjacent lightemitting diodes are closer to a center of the substrate in the firstdirection; the substrate is divided into a first divided substrate and asecond divided substrate between adjacent light emitting diodes providedat a position away from a position at which adjacent light emittingdiodes having a smallest pitch among the pitches are provided; at leastone of the first divided substrate and the second divided substrateincludes, at one end portion of the at least one of the first dividedsubstrate and the second divided substrate, a cable connector forconnection to a cable; and the first divided substrate and the seconddivided substrate are disposed so that another end portion of the firstdivided substrate and another end portion of the second dividedsubstrate are adjacent to each other.
 6. A liquid crystal displaydevice, comprising: a liquid crystal display panel having a displaysurface and a rear surface, which is on a side opposite to the displaysurface; and a backlight, wherein: the backlight comprises: a pluralityof light emitting diodes; a substrate on which the plurality of lightemitting diodes are mounted; and a reflection sheet, which overlaps thesubstrate at a surface on which the plurality of light emitting diodesare mounted in a manner without overlapping the plurality of lightemitting diodes; the surface on which the plurality of light emittingdiodes are mounted of the substrate is opposed to the rear surface ofthe liquid crystal display panel; the liquid crystal display panel andthe substrate each have a shape in which a common width in a firstdirection is longer than a width in a second direction, which isorthogonal to the first direction; the width of the substrate in thesecond direction is shorter than the width of the liquid crystal displaypanel in the second direction, the substrate being opposed to, whileavoiding being opposed to both end portions of the liquid crystaldisplay panel in the second direction, a central portion between theboth end portions of the liquid crystal display panel; pitches betweenadjacent light emitting diodes of the plurality of light emitting diodesare smaller as the adjacent light emitting diodes are closer to a centerof the substrate in the first direction; the substrate is divided into afirst divided substrate, a second divided substrate, and a third dividedsubstrate between adjacent light emitting diodes provided at positionsaway from a position at which adjacent light emitting diodes having asmallest pitch among the pitches are provided; a cable connector forconnection to a cable, which is provided at one end portion of the firstdivided substrate; a first substrate connector for electricallyconnecting another end portion of the first divided substrate and oneend portion of the second divided substrate; and a second substrateconnector for electrically connecting another end portion of the seconddivided substrate and one end portion of the third divided substrate. 7.The liquid crystal display device according to claim 6, wherein: theplurality of light emitting diodes are arranged in a staggered patternin the first direction; and the pitches between adjacent light emittingdiodes of the plurality of light emitting diodes correspond to pitchesbetween adjacent light emitting diodes of the plurality of lightemitting diodes in an arrangement direction of the staggered pattern. 8.The liquid crystal display device according to claim 7, wherein: theanother end portion of the first divided substrate and the one endportion of the second divided substrate, which are electricallyconnected to each other, each have a recess portion and a convex portionat surfaces which are opposed to each other; the another end portion ofthe second divided substrate and the one end portion of the thirddivided substrate, which are electrically connected to each other, eachhave a recess portion and a convex portion at surfaces which are opposedto each other; the convex portion is protruded in the first directionfrom one of the plurality of light emitting diodes, which is positionedoutermost in the first direction of each of the first divided substrate,the second divided substrate, and the third divided substrate; the firstdivided substrate and the second divided substrate are disposed so thatthe recess portion of one divided substrate is opposed to the convexportion of another divided substrate; and the second divided substrateand the third divided substrate are disposed so that the recess portionof one divided substrate is opposed to the convex portion of anotherdivided substrate.
 9. The liquid crystal display device according toclaim 6, wherein: light emitting diodes, which are disposed on thesecond divided substrate, of the plurality of light emitting diodes arearranged in a staggered pattern in the first direction, and pitchesbetween adjacent light emitting diodes of the light emitting diodescorrespond to pitches between adjacent light emitting diodes of thelight emitting diodes in an arrangement direction of the staggeredpattern; and light emitting diodes, which are disposed on the firstdivided substrate, and light emitting diodes, which are disposed on thethird divided substrate, of the plurality of light emitting diodes arerespectively arranged in a row in the first direction.
 10. The liquidcrystal display device according to claim 9, wherein a width of thesecond divided substrate in the second direction is larger than any oneof a width of the first divided substrate in the second direction and awidth of the third divided substrate in the second direction.
 11. Aliquid crystal display device, comprising: a liquid crystal displaypanel having a display surface and a rear surface, which is on a sideopposite to the display surface; and a backlight, wherein: the backlightcomprises: a plurality of light emitting diodes; a substrate on whichthe plurality of light emitting diodes are mounted; and a reflectionsheet, which overlaps the substrate at a surface on which the pluralityof light emitting diodes are mounted in a manner without overlapping theplurality of light emitting diodes; the surface on which the pluralityof light emitting diodes are mounted of the substrate is opposed to therear surface of the liquid crystal display panel; the liquid crystaldisplay panel and the substrate each have a shape in which a commonwidth in a first direction is longer than a width in a second direction,which is orthogonal to the first direction; the width of the substratein the second direction is shorter than the width of the liquid crystaldisplay panel in the second direction, the substrate being opposed to,while avoiding being opposed to both end portions of the liquid crystaldisplay panel in the second direction, a central portion between theboth end portions of the liquid crystal display panel; the backlightincludes the reflection sheet as a first reflection sheet, and a secondreflection sheet, which is adhered to the substrate; the firstreflection sheet includes a plurality of first holes, which allow theplurality of light emitting diodes to be respectively disposed on innersides of the first reflection sheet; the second reflection sheetincludes, as a whole, a plurality of second holes, which allow theplurality of light emitting diodes to be respectively disposed on innersides of the second reflection sheet; and on an inner side of each ofthe plurality of first holes, at least a part of an edge portion ofcorresponding one of the plurality of second holes is exposed.
 12. Theliquid crystal display device according to claim 11, wherein: the secondreflection sheet is divided into a plurality of reflection pieces; oneof the plurality of reflection pieces includes one of the plurality ofsecond holes, which allows one of the plurality of light emitting diodesto be disposed on an inner side of the one of the plurality ofreflection pieces; pitches between adjacent light emitting diodes of theplurality of light emitting diodes are smaller as the adjacent lightemitting diodes are closer to a center of the substrate in the firstdirection; and each of the plurality of reflection pieces is formed insuch a size and a shape that, at a position corresponding to adjacentlight emitting diodes having a smallest pitch among the pitches,adjacent reflection pieces are provided without overlapping each other.13. The liquid crystal display device according to claim 11, wherein:the second reflection sheet is divided into a first reflection piece,which is disposed in a first region at a center of the substrate, and aplurality of second reflection pieces, which are disposed at a pair ofsecond regions of the substrate, which sandwich the first region; andpitches between adjacent light emitting diodes of the plurality of lightemitting diodes are smaller as the adjacent light emitting diodes arecloser to the center of the substrate in the first direction.
 14. Theliquid crystal display device according to claim 13, wherein: the firstreflection piece includes at least two of the plurality of second holes;and each of the plurality of second reflection pieces includes one ofthe plurality of second holes.
 15. The liquid crystal display deviceaccording to claim 13, wherein: the first reflection piece includes atleast two of the plurality of second holes; and each of the plurality ofsecond reflection pieces includes at least two of the plurality ofsecond holes.
 16. The liquid crystal display device according to claim13, wherein at least the light emitting diodes, which are disposed inthe first region, are arranged in a staggered pattern in the firstdirection.
 17. The liquid crystal display device according to claim 16,wherein the light emitting diodes, which are disposed in the secondregion, are arranged in a row in the first direction.
 18. The liquidcrystal display device according to claim 11, wherein: the secondreflection sheet is divided into a plurality of reflection pieces; eachof the plurality of reflection pieces includes at least two of theplurality of second holes, which allow at least two of the plurality oflight emitting diodes to be disposed on inner sides of the at least twoof the plurality of reflection pieces; the substrate is divided into aplurality of divided substrates; and each of the plurality of reflectionpieces has an outer shape which is similar to one of the plurality ofdivided substrates to which corresponding one of the plurality ofreflection pieces is adhered.
 19. The liquid crystal display deviceaccording to claim 11, wherein the second reflection sheet is formed byapplying a white resist onto the substrate.